Influence of surface preheating and pretreatment on the adhesion of laser-melted PEEK to aluminum substrates

The high-performance polymer Polyether ether ketone (PEEK) is commonly used as friction-reducing coating in many areas of mechanical engineering. However, the coating of temperature-sensitive components is only possible to a limited extent due to the high hardness loss of the component during conventional oven processing at elevated temperatures to melt the PEEK layers. Alternatively, laser radiation can be used to melt the particulate PEEK layers and simultaneously reduce the thermal load on the substrate. A key challenge of these processes, however, lies in ensuring sufficient adhesion between the molten PEEK layer and the metal substrate. This study addresses the laser pretreatment of EN AW 6082 aluminum and investigates how the surface topography and preheating temperature of the substrate affect the adhesion behavior of the PEEK layer after laser-based melting as well as the hardness loss of the substrate during laser melting. • Laser melting of PEEK reduces substrate hardness loss by 81 % compared to oven melting. • Preheating of the substrate surface determines the adhesion strength of PEEK coatings. • Laser pretreatment of aluminum can increase the absorbance of the surface by 50 %.